Numerous cleaning devices capable of autonomous movement within swimming pools and spas currently exist. The most common of these devices are APCs, which often are either hydraulic or robotic in type. Hydraulic cleaners vary water flow for movement, while robotic cleaners typically employ electric motors to cause motion. Hydraulic APCs, furthermore, subdivide into “pressure-side” and “suction-side” cleaners, with pressure-side cleaners being fluidly connected to outputs of pumps of pool water circulation systems and suction-side cleaners being fluidly connected to inputs of such pumps.
Water vacuumed into suction-side cleaners typically is filtered remotely. By contrast, robotic and pressure-side APCs usually include on-board filtration, with a filter carried on, in, or with an associated body of an APC as the body moves within a pool. Because the filters frequently are submerged in use and often positioned within the bodies of many robotic cleaners, they are not easily visible externally of the pools. Clogging of the filters thus may remain unnoticed for extended periods, significantly reducing the cleaning and operational efficiencies of the corresponding APCs.
Various methods have been devised to resolve issues of filter clogging of APCs. U.S. Pat. No. 5,961,822 to Polimeni, Jr., for example, describes a non-autonomous pool cleaner utilizing one or more rolls of “a continuous sheet of filter material.” As the sheet clogs with debris, water accumulates inside the filter so as to contact a float switch. The float switch in turn activates a motor which advances the roll of filter material so that an unclogged portion is exposed to the debris-laden water.
U.S. Patent Application Publication No. 2015/0191926 of Tavor, et al., discloses a robotic pool cleaner having a two-chamber filter. As debris accumulates in the first chamber, it may be sensed by an optical detector and moved—via automatic backwashing—to a second chamber of the filter. A non-return valve is employed to prevent debris in the second chamber from returning to the first chamber. Nevertheless, acknowledged in the Tavor application is that, from time to time, debris must be removed from the second chamber manually.
The entire contents of the Polimeni, Jr. patent and the Tavor application are incorporated herein by this reference. Both filings seek to reduce filter clogging through automatic activity when a switch or sensor changes state. Neither, however, contemplates notifying a user or operator of a pool that the on-board filter of an APC is clogged.
U.S. Pat. No. 6,965,814 to Hadari, whose entire contents also are incorporated herein by this reference, details another robotic cleaner having a replaceable bag filter. The robot additionally includes a controller which periodically samples current to an impeller motor. As noted in the Hadari patent: “When the instantaneous sampled current exceeds a preset threshold value, . . . [the controller] issues a signal activating an indicator, e.g., a warning light, showing that the filter is partly clogged.” No clogging assessment is contemplated other than based on sampled current to the motor, however.